The present invention relates to structural elements for motor vehicles, and more particularly to a rear structural element.
It is known to make motor vehicles by assembling various structural elements on a platform, which elements are in turn intended to support equipment such as elements of bodywork, a bumper, or lights.
To vary the style of the rear portions of vehicles, the sub-frames of the platform have modified rear portions.
The fact that different sub-frames are used complicates vehicle manufacture and increases cost price.
In addition, the rear portion of known motor vehicles is constituted by assembling together a relatively large number of structural elements, which has consequences on the surface treatments that need to be performed and on the time and number of operations needed to assemble the vehicle.
Finally, numerous structural elements of the rear portion of the vehicle are assembled together by welding, which makes them difficult to replace in the event of an accident, and gives rise to repair costs that are relatively high.
French patent No. FR-B-2 773 132 discloses a floor structure for a motor vehicle, which structure includes a basin of plastics material for receiving, in particular, a spare wheel. The basin is extend rearwards by a beam which serves to support a rear shield. The beam is arranged to bear against a metal cross-member fixed at each of its ends to the side walls of the vehicle. The presence of the metal cross-member significantly limits the amount of styling modification that can be applied to the rear portion of the vehicle. In addition, in the event of an accident, the cross-member can be damaged. Since the cross-member is not designed to be easily removed, repair costs are relatively high.
German patent application DE 199 13 532 describes a motor vehicle rear module comprising a reinforcing frame having elements, in particular a bumper, a tailgate, lights, and a reinforcing metal sheet preassembled thereon. The assembled module is put into place on the rear structure of the vehicle, and in particular it is fixed to the side rails. In the event of an accident, the reinforcing frame can be damaged, in which case it needs to be removed together with all of the elements it supports and replaced by a new frame, thus giving rise to repair that is complex and expensive.
A particular object of the present invention is to enable a car manufacturer to standardized platforms without harming the variety of styles on offer.
Another object of the invention is to reduce the cost of modifying the styling of a vehicle.
Another object of the invention is to reduce the cost of repairs, and also the time and the number of operations that are necessary for assembling the vehicle.
The invention provides a module forming all or part of the rear end of a motor vehicle, being suitable for being fitted to the side rails and to the rear side portions of the motor vehicle, said module comprising at least two releasable side portions and being arranged to receive or already including items of equipment.
This makes it possible to replace only a portion of the module in the event of only part of it being damaged, e.g. one of its two side portions.
The above-mentioned equipment can be selected, for example, from the following list: an impact-absorber beam; a floor; a rear shield; signaling devices; elements for sealing the vehicle cabin; elements for locking a door; and elements of the system for filling the fuel tank.
It is particularly advantageous for the rear module already to include a rear shield when it is mounted on the vehicle.
In addition to the two side portions, the module preferably also includes a central portion, the side portions being assembled to said central portion.
Advantageously, the fastenings between the central portion and the side portions are fastenings that are easily undone, which is advantageous if it is necessary to replace a portion of the module following an accident.
The module preferably has no welding between its component elements.
Also preferably, the module includes portions that enable it to be fastened without welding to the side rails and possibly also to the rear side portions of the vehicle body.
In a particular embodiment, the module is secured to a floor, which can be formed integrally with the central portion of the module or can be constituted by an element that is fitted thereto, in which case it is advantageous for the central portion of the module and the floor to be delivered to the car manufacturer in the assembled state.
The module can have side rail extenders and/or floor extenders, where such extenders can be fitted to the remainder of the module.
In the preassembled state, the floor can include trim for the trunk of the vehicle.
The floor can also have cavities enabling accessories and/or a spare wheel to be stored.
The floor can also include heat screens and/or sound screens together with elements for fastening items of equipment such as the exhaust muffler or the fuel tank.
In a particular embodiment, the module has link means fitted thereto or integrated therein for the purpose of supporting adjacent bodywork elements, e.g. a rear fender.
Advantageously, such link means are arranged so as to be capable of accommodating docking tolerances and/or differential expansion relative to bodywork elements.
Advantageously, the rear module includes housings for receiving or forming a portion of the lights, in particular signaling light inserts.
The rear module can also include means enabling a back door to be mounted, to pivot about a horizontal axis in the vicinity of its bottom edge.
In a particular embodiment, the module has a face that is visible from inside the vehicle, which makes it possible to avoid the need to fit additional trim for the purpose of covering it.
On its inside face, the module can have decorative elements that are specific to a given vehicle, where such decorative elements are advantageously delivered to the manufacturer preassembled with the rear module.
The module can also have channels for guiding electric wires, e.g. for the purpose of making it easier to install lights.
The invention also provides a novel method of manufacturing a motor vehicle, the method being characterized by the fact that it includes the following step:
fitting a structural rear module to the side rails and to the rear side portions of the vehicle body, said structural rear module comprising a small number of preassembled component elements, forming all or part of the rear end of the vehicle structure, and being designed to receive or already supporting items of equipment, said module comprising at least two releasable side portions.
By way of example, these items of equipment can be selected from the following list: an impact-absorbing beam; a floor; a rear shield; signaling devices; elements for providing sealing for the vehicle cabin; elements for locking a door; and elements of a system for filling the fuel tank.
When the module includes a floor, the module and the floor can be preassembled.
The invention makes it possible for the car manufacturer to standardized platforms while giving special styling by selecting which rear module is to be used.
This makes it possible to diversify vehicle styles at lower investment and lower cost, since there is no need to modify the platform as a function of which rear module is to be used, all of the rear modules being arranged so as to allow them to be secured to a standard platform.
The rear module replaces in particular the cross-member of a conventional platform, and as a result platforms no longer have to include cross-members that are specific to particular vehicle styles.
In addition, because the structure of the rear module enables it to be delivered to a manufacturer in an already fitted-out state, the time and the number of operations required for assembling the vehicle are decreased.
The rear module of the invention has a small number of parts, preferably fewer than five and more preferably still three, i.e. a central portion and two side portions.